diff --git a/core/lib/core/domain/invoker.ex b/core/lib/core/domain/invoker.ex
index b1a9c2f..0e001f7 100644
--- a/core/lib/core/domain/invoker.ex
+++ b/core/lib/core/domain/invoker.ex
@@ -19,7 +19,6 @@ defmodule Core.Domain.Invoker do
   require Logger
 
   alias Core.FunctionsMetadata
-  alias Data.FunctionMetadata
 
   alias Core.Domain.{
     Functions,
diff --git a/data/lib/function_metadata.ex b/data/lib/function_metadata.ex
index 4e9cb0e..68505ec 100644
--- a/data/lib/function_metadata.ex
+++ b/data/lib/function_metadata.ex
@@ -24,5 +24,5 @@ defmodule Data.FunctionMetadata do
           tag: String.t(),
           capacity: integer()
         }
-  defstruct tag: nil, capacity: -1
+  defstruct tag: "", capacity: -1
 end